Gamma-ray irradiation apparatus and supporting structure



April 6, 1965 Boz l E 3,177,365

GAMMA-RAY IRRADIATION APPARATUS AND SUPPORTING STRUCTURE Filed June 20, 1962 2 Sheets-Sheet 1 April 6, 1965 1.. sozKl ETAL 3,177,365

GAMMA-RAY IRRADIATION APPARATUS AND SUPPORTING STRUCTURE Filed June 20, 1962 2 Sheets-Sheet 2 United States Patent 0.

3,177,365 GAMMA-RAY HQRADHATHGN APPARATUS AND SUPPGRTHNG STRUCTURE Laszl Bozom, lstvan Martos, and lstvan Wain, Budapest,

li-llungmy, assignors to Medicor Riintgen Miivek, Budapest, Hungary, a firm Filed June 20, 1962, Ser. No. ZMMH 3 Claims. (6i. 2541-105) This invention relates to an irradiation apparatus for medical and scientific purposes, the radiation source of which is a radioactive substance such as cobalt-60 or caesium-137.

Apparatus of this type is known in both stationary and movable construction. Special care must be paid to radiation protection in the construction of the apparatus particularly having regard to the latest and stringent regulations of the International Radiation Protection Commission. Consequently, the isotope-containing irradiation head of such apparatus has gradually become heavier, since the activity of the sources has increased, and the dosage of the harmful rays emergent from the irradiator head has also had to be continuously reduced.

The increase in weight of the irradiator head gives rise to considerable difficulties, particularly in the case of rotary apparatus, since in the latter, the irradiator head has to be advanced along an are about the centre of rotation in such a manner that the useful beam of rays is directed always towards the centre. At the same time, modern deep therapy is making increasing demands on such rotary apparatus.

in apparatus according to the invention a radiation source is movable from an irradiator head to a storage piace through a tube which rigidly connects the head and storage place and the entire device can be rotated about a horizontal shaft in such a manner that the beam of rays from the radiation source when it is in the irradiator head always passes through a predetermined point.

The device according to the invention ensures protec tion from radiation for the physician or nurse during the adjustment of the patient, due to the fact that during adjustment, the radiation source leaves the irradiator head and hence forms no radiation load of any kind for the persons effecting the adjustment, and considerably reduces the weight of the irradiator head moving over the patient, and thus also increases the mechanical safety. The construction according to the invention transfers the radiation screening, representing a considerable weight, from the irradiator head to the Wall of the room, where also the reduction of the dosage of harmful radiation to the level of background radiation can also be realised in a simple manner. Only the radiation protection necessary for the patient and forming only a fraction of the weight to be accommodated in the wall is to be retained on the irradiator head.

The invention will be further described with reference to the accompanying drawings in which:

FIGURE 1 shows a constructional example of apparatus embodying the invention;

FIGURE 2 shows a construction of irradiator head; and

FIGURE 3 shows apparatus for moving the radiation source.

As shown in FIGURE 1 a container head 5 accommodated in the wall can be rotated, together with an irradiator head 4, situated on a holding arm 6 (which latter is rigidly connected to said container head) jointly about a rotation shaft 11 by motor drive at a previously adjusted speed.

A radiation source 3 is arranged between two lead cylinders 2% in a shell, which can be pushed into the irradiator head 4 via a steel tube '7 mounted eccentrically Patented Apr. 6, 1965 in the outer holding arm 6. The lead layer provided between the two tubes serves to protect the patient from radiation during the passage of the radiation source. Irradiation can be carried out with beams, the cross-section of which, at right angles to the axis of rotation pasing through point 1 in FIGURE 1, can be varied.

The rotating part is balanced about its horizontal axis by the counterpoise l9, and its centre of gravity in the longitudinal direction falls between the two bearings of the rotation shaft. The stability of the device is thereby ensured, While at the same time its movement demands a comparatively small expenditure of power. The rotatable part 9 of the wall is situated in the concrete wall 8, and these two jointly ensure radiation protection of the adjacent room in which the mechanical driving devices are accommodated.

The construction of the irradiator head can be appreciated from FIGURE 2. Irradiation of the desired crosssection is obtained by means of the conical ray exit orifice 21 provided in the lead ball 4 and exchangeable lead diaphragms Z2 situated therein, as soon as the radiation source has reached the tip of the cone. Movement of the shell containing the radiation source is produced by means of the rod 13 with the aid of the mechanism shown in FIGURE 3.

The suspension of the driving mechanism is effected at the point of intersection of the rotation shaft and the prolongation of the steel tube '7, whereby the latter is able to follow the movement of rotation. The end point of the rod 13 transmitting the movement is carried by the wheel 23 running on the guide rail 14, the wire cable producing said movement being connected to said wheel. Fixed to one end of the wire cable is the weight 16 producing the return movement of the shell, while fixed to the other end is a connecting member 17, by means of which the Weight 15 (which is heavier than the Weight in) produces the inward movement of the shell. Preparation for irradiation is made by pulling up of the weight 15, which is fixed automatically in its pulled-up position. After release of the fixing means, the weight 15 acting by means of the connecting member 17 pushes the shell into the irradiator head, the weight 16 being pulled up automatically. Cessation of irradiation is brought about by breaking the connection between the weight 15 and the connecting member 17, the shell being then returned to its position in the wall by the weight 16. Uniform movement of the shell is ensured by the air brake provided in the isotope guide tube 7.

What we claim is:

1. A beam forming unit comprising a source of gammaray radiations, a radiator head for receiving said source and allowing the emission of radiations therefrom, a storage chamber for receiving said source and preventing the emission of radiations therefrom, a hollow tube disposed at an angle to a horizontal plane connecting said radiator head and said storage chamber and movably supporting said source therein, support means supporting said storage chamber for rotation about a horizontal axis, a movable element having one end projecting into said tube adjacent said source for moving said source from said storage chamber to said radiator head, and driving means connected to the outer end of said element for periodically moving said element into said tube to push said source into said radiator head for a predetermined interval of time, said driving means being supported at the intersection of the axis of said tube and said horizontal axis and at the end of said tube.

2. A beam-forming unit as defined in claim 1, wherein said support means comprises a drum, bearings mounting said drum for said rotation about the horizontal axis, said drum and storage chamber forming a portion of the Wall enclosing the radiator head.

connected to said last-named means intermediate its length, a first weight tied to one end of said cable and adapted to pull said pulley down the track to move said movable element out of said tube to allow said source to move to said storage chamber, a second weight being heavier than said first Weight, said second weight connected to the, other end of said cable, said second weight adapted to pull said pulley up the track to move said movable element into said tube thereby moving said source to said radiator head, means connected to said said tube is withdrawn and said source is in said storage means,-and means connected between said second Weight and said cable for breaking the connection between said second weight and cable to allow said first Weight to cause said element to move out of said tube.

References Cited by the Examiner UNITED STATES PATENTS 2,711,485 6/55 Pennock 250108 2,750,517 6/56 Baum 250106 2,872,587 2/59 Stein 250106 2,951,162 8/60 Stein 250106 cable for fixing said second weight in a position whereby 15 RALPH NILSON, Examine"- 

1. A BEAM FORMING UNIT COMPRISING A SOURCE OF GAMMARAY RADIATIONS, A RADIATOR HEAD FOR RECEIVING SAID SOURCE AND ALLOWING THE EMISSION OF RADIATIONS THEREFROM, A STORAGE CHAMBER FOR RECEIVING SAID SOURCE AND PREVENTING THE EMISSION OF RADIATIONS THEREFROM, A HOLLOW TUBE DISPOSED AT AN ANGLE TO A HORIZONTAL PLANE CONNECTING SAID RADIATOR HEAD AND SAID STORAGE CHAMBER AND MOVABLY SUPPORTING SAID SOURCE THEREIN, SUPPORT MEANS SUPPORTING SAID STORAGE CHAMBER FOR ROTATION ABOUT A HORIZONTAL AXIS, A MOVABLE ELEMENT HAVING ONE END PROJECTING INTO SAID TUBE ADJACENT SAID SOURCE FOR MOVING SAID SOURCE FROM SAID STORAGE CHAMBER TO SAID RADIATOR HEAD, AND DRIVING MEANS CONNECTED TO THE OUTER END OF SAID ELEMENT FOR PERIODICALLY MOVING SAID ELEMENT INTO SAID TUBE TO PUSH SAID SOURCE INTO SAID RADIATOR HEAD FOR A PREDETERMINED INTERVAL OF TIME, SAID DRIVING MEANS BEING SUPPORTED AT THE INTERSECTION OF THE AXIS OF SAID TUBE AND SAID HORIZONTAL AXIS AND AT THE END OF SAID TUBE. 